<!DOCTYPE html>
<html>
    <body>
        
    <p>
            点击下面的按钮，将代码块循环五次：
    </p>
    <button onclick="myFunction()">点击这里</button>
    <p id="demo"></p>
    <script>
     function myFunction(){
         var x="";
         for (var i=0;i<5;i++)
         {
             x=x+"the numer is" +i +"<br/>";
         }
         document.getElementById("demo").innerHTML=x;
     }
    </script>
    </body>
</html>